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1113ff44 MR |
1 | ;;; help-fns.el --- Complex help functions |
2 | ||
a87b98ce GM |
3 | ;; Copyright (C) 1985, 1986, 1993, 1994, 1998, 1999, 2000, 2001, 2002, |
4 | ;; 2003, 2004, 2005, 2006, 2007, 2008, 2009 | |
589a99f2 | 5 | ;; Free Software Foundation, Inc. |
1113ff44 MR |
6 | |
7 | ;; Maintainer: FSF | |
8 | ;; Keywords: help, internal | |
9 | ||
10 | ;; This file is part of GNU Emacs. | |
11 | ||
12 | ;; GNU Emacs is free software: you can redistribute it and/or modify | |
13 | ;; it under the terms of the GNU General Public License as published by | |
14 | ;; the Free Software Foundation, either version 3 of the License, or | |
15 | ;; (at your option) any later version. | |
16 | ||
17 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
18 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | ;; GNU General Public License for more details. | |
21 | ||
22 | ;; You should have received a copy of the GNU General Public License | |
23 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. | |
24 | ||
25 | ;;; Commentary: | |
26 | ||
27 | ;; This file contains those help commands which are complicated, and | |
28 | ;; which may not be used in every session. For example | |
29 | ;; `describe-function' will probably be heavily used when doing elisp | |
30 | ;; programming, but not if just editing C files. Simpler help commands | |
31 | ;; are in help.el | |
32 | ||
33 | ;;; Code: | |
34 | ||
35 | (require 'help-mode) | |
36 | ||
37 | ;; Functions | |
38 | ||
39 | ;;;###autoload | |
40 | (defun describe-function (function) | |
41 | "Display the full documentation of FUNCTION (a symbol)." | |
42 | (interactive | |
43 | (let ((fn (function-called-at-point)) | |
44 | (enable-recursive-minibuffers t) | |
45 | val) | |
46 | (setq val (completing-read (if fn | |
47 | (format "Describe function (default %s): " fn) | |
48 | "Describe function: ") | |
49 | obarray 'fboundp t nil nil | |
50 | (and fn (symbol-name fn)))) | |
51 | (list (if (equal val "") | |
52 | fn (intern val))))) | |
53 | (if (null function) | |
54 | (message "You didn't specify a function") | |
55 | (help-setup-xref (list #'describe-function function) (interactive-p)) | |
56 | (save-excursion | |
57 | (with-help-window (help-buffer) | |
58 | (prin1 function) | |
59 | ;; Use " is " instead of a colon so that | |
60 | ;; it is easier to get out the function name using forward-sexp. | |
61 | (princ " is ") | |
62 | (describe-function-1 function) | |
63 | (with-current-buffer standard-output | |
64 | ;; Return the text we displayed. | |
65 | (buffer-string)))))) | |
66 | ||
67 | (defun help-split-fundoc (docstring def) | |
68 | "Split a function DOCSTRING into the actual doc and the usage info. | |
69 | Return (USAGE . DOC) or nil if there's no usage info. | |
70 | DEF is the function whose usage we're looking for in DOCSTRING." | |
71 | ;; Functions can get the calling sequence at the end of the doc string. | |
72 | ;; In cases where `function' has been fset to a subr we can't search for | |
73 | ;; function's name in the doc string so we use `fn' as the anonymous | |
74 | ;; function name instead. | |
75 | (when (and docstring (string-match "\n\n(fn\\(\\( .*\\)?)\\)\\'" docstring)) | |
76 | (cons (format "(%s%s" | |
77 | ;; Replace `fn' with the actual function name. | |
78 | (if (consp def) "anonymous" def) | |
79 | (match-string 1 docstring)) | |
80 | (substring docstring 0 (match-beginning 0))))) | |
81 | ||
82 | (defun help-add-fundoc-usage (docstring arglist) | |
83 | "Add the usage info to DOCSTRING. | |
84 | If DOCSTRING already has a usage info, then just return it unchanged. | |
85 | The usage info is built from ARGLIST. DOCSTRING can be nil. | |
86 | ARGLIST can also be t or a string of the form \"(FUN ARG1 ARG2 ...)\"." | |
87 | (unless (stringp docstring) (setq docstring "Not documented")) | |
88 | (if (or (string-match "\n\n(fn\\(\\( .*\\)?)\\)\\'" docstring) (eq arglist t)) | |
89 | docstring | |
90 | (concat docstring | |
91 | (if (string-match "\n?\n\\'" docstring) | |
92 | (if (< (- (match-end 0) (match-beginning 0)) 2) "\n" "") | |
93 | "\n\n") | |
94 | (if (and (stringp arglist) | |
95 | (string-match "\\`([^ ]+\\(.*\\))\\'" arglist)) | |
96 | (concat "(fn" (match-string 1 arglist) ")") | |
97 | (format "%S" (help-make-usage 'fn arglist)))))) | |
98 | ||
99 | (defun help-function-arglist (def) | |
100 | ;; Handle symbols aliased to other symbols. | |
101 | (if (and (symbolp def) (fboundp def)) (setq def (indirect-function def))) | |
102 | ;; If definition is a macro, find the function inside it. | |
ced10a4c SM |
103 | (let ((advertised (gethash def advertised-signature-table t))) |
104 | (if (listp advertised) advertised | |
105 | (if (eq (car-safe def) 'macro) (setq def (cdr def))) | |
106 | (cond | |
107 | ((byte-code-function-p def) (aref def 0)) | |
108 | ((eq (car-safe def) 'lambda) (nth 1 def)) | |
109 | ((and (eq (car-safe def) 'autoload) (not (eq (nth 4 def) 'keymap))) | |
110 | "[Arg list not available until function definition is loaded.]") | |
111 | (t t))))) | |
1113ff44 MR |
112 | |
113 | (defun help-make-usage (function arglist) | |
114 | (cons (if (symbolp function) function 'anonymous) | |
115 | (mapcar (lambda (arg) | |
116 | (if (not (symbolp arg)) | |
117 | (if (and (consp arg) (symbolp (car arg))) | |
118 | ;; CL style default values for optional args. | |
119 | (cons (intern (upcase (symbol-name (car arg)))) | |
120 | (cdr arg)) | |
121 | arg) | |
122 | (let ((name (symbol-name arg))) | |
123 | (if (string-match "\\`&" name) arg | |
124 | (intern (upcase name)))))) | |
125 | arglist))) | |
126 | ||
127 | ;; Could be this, if we make symbol-file do the work below. | |
128 | ;; (defun help-C-file-name (subr-or-var kind) | |
129 | ;; "Return the name of the C file where SUBR-OR-VAR is defined. | |
130 | ;; KIND should be `var' for a variable or `subr' for a subroutine." | |
131 | ;; (symbol-file (if (symbolp subr-or-var) subr-or-var | |
132 | ;; (subr-name subr-or-var)) | |
133 | ;; (if (eq kind 'var) 'defvar 'defun))) | |
134 | ;;;###autoload | |
135 | (defun help-C-file-name (subr-or-var kind) | |
136 | "Return the name of the C file where SUBR-OR-VAR is defined. | |
137 | KIND should be `var' for a variable or `subr' for a subroutine." | |
138 | (let ((docbuf (get-buffer-create " *DOC*")) | |
139 | (name (if (eq 'var kind) | |
140 | (concat "V" (symbol-name subr-or-var)) | |
141 | (concat "F" (subr-name subr-or-var))))) | |
142 | (with-current-buffer docbuf | |
143 | (goto-char (point-min)) | |
144 | (if (eobp) | |
145 | (insert-file-contents-literally | |
146 | (expand-file-name internal-doc-file-name doc-directory))) | |
147 | (let ((file (catch 'loop | |
148 | (while t | |
149 | (let ((pnt (search-forward (concat "\1f" name "\n")))) | |
150 | (re-search-backward "\1fS\\(.*\\)") | |
151 | (let ((file (match-string 1))) | |
152 | (if (member file build-files) | |
153 | (throw 'loop file) | |
154 | (goto-char pnt)))))))) | |
155 | (if (string-match "^ns.*\\(\\.o\\|obj\\)\\'" file) | |
156 | (setq file (replace-match ".m" t t file 1)) | |
157 | (if (string-match "\\.\\(o\\|obj\\)\\'" file) | |
158 | (setq file (replace-match ".c" t t file)))) | |
159 | (if (string-match "\\.\\(c\\|m\\)\\'" file) | |
160 | (concat "src/" file) | |
161 | file))))) | |
162 | ||
1659ada0 JB |
163 | (defcustom help-downcase-arguments nil |
164 | "If non-nil, argument names in *Help* buffers are downcased." | |
165 | :type 'boolean | |
166 | :group 'help | |
167 | :version "23.2") | |
168 | ||
169 | (defun help-highlight-arg (arg) | |
170 | "Highlight ARG as an argument name for a *Help* buffer. | |
171 | Return ARG in face `help-argument-name'; ARG is also downcased | |
172 | if the variable `help-downcase-arguments' is non-nil." | |
173 | (propertize (if help-downcase-arguments (downcase arg) arg) | |
174 | 'face 'help-argument-name)) | |
1113ff44 MR |
175 | |
176 | (defun help-do-arg-highlight (doc args) | |
177 | (with-syntax-table (make-syntax-table emacs-lisp-mode-syntax-table) | |
178 | (modify-syntax-entry ?\- "w") | |
179 | (dolist (arg args doc) | |
180 | (setq doc (replace-regexp-in-string | |
181 | ;; This is heuristic, but covers all common cases | |
182 | ;; except ARG1-ARG2 | |
183 | (concat "\\<" ; beginning of word | |
184 | "\\(?:[a-z-]*-\\)?" ; for xxx-ARG | |
185 | "\\(" | |
186 | (regexp-quote arg) | |
187 | "\\)" | |
188 | "\\(?:es\\|s\\|th\\)?" ; for ARGth, ARGs | |
189 | "\\(?:-[a-z0-9-]+\\)?" ; for ARG-xxx, ARG-n | |
190 | "\\(?:-[{([<`\"].*?\\)?"; for ARG-{x}, (x), <x>, [x], `x' | |
191 | "\\>") ; end of word | |
1659ada0 | 192 | (help-highlight-arg arg) |
1113ff44 MR |
193 | doc t t 1))))) |
194 | ||
195 | (defun help-highlight-arguments (usage doc &rest args) | |
196 | (when usage | |
197 | (with-temp-buffer | |
198 | (insert usage) | |
199 | (goto-char (point-min)) | |
200 | (let ((case-fold-search nil) | |
201 | (next (not (or args (looking-at "\\[")))) | |
202 | (opt nil)) | |
203 | ;; Make a list of all arguments | |
204 | (skip-chars-forward "^ ") | |
205 | (while next | |
206 | (or opt (not (looking-at " &")) (setq opt t)) | |
207 | (if (not (re-search-forward " \\([\\[(]*\\)\\([^] &)\.]+\\)" nil t)) | |
208 | (setq next nil) | |
209 | (setq args (cons (match-string 2) args)) | |
210 | (when (and opt (string= (match-string 1) "(")) | |
211 | ;; A pesky CL-style optional argument with default value, | |
212 | ;; so let's skip over it | |
213 | (search-backward "(") | |
214 | (goto-char (scan-sexps (point) 1))))) | |
215 | ;; Highlight aguments in the USAGE string | |
216 | (setq usage (help-do-arg-highlight (buffer-string) args)) | |
217 | ;; Highlight arguments in the DOC string | |
218 | (setq doc (and doc (help-do-arg-highlight doc args)))))) | |
219 | ;; Return value is like the one from help-split-fundoc, but highlighted | |
220 | (cons usage doc)) | |
221 | ||
222 | ;; The following function was compiled from the former functions | |
223 | ;; `describe-simplify-lib-file-name' and `find-source-lisp-file' with | |
224 | ;; some excerpts from `describe-function-1' and `describe-variable'. | |
225 | ;; The only additional twists provided are (1) locate the defining file | |
226 | ;; for autoloaded functions, and (2) give preference to files in the | |
227 | ;; "install directory" (directories found via `load-path') rather than | |
228 | ;; to files in the "compile directory" (directories found by searching | |
229 | ;; the loaddefs.el file). We autoload it because it's also used by | |
230 | ;; `describe-face' (instead of `describe-simplify-lib-file-name'). | |
231 | ||
232 | ;;;###autoload | |
233 | (defun find-lisp-object-file-name (object type) | |
234 | "Guess the file that defined the Lisp object OBJECT, of type TYPE. | |
235 | OBJECT should be a symbol associated with a function, variable, or face; | |
236 | alternatively, it can be a function definition. | |
237 | If TYPE is `variable', search for a variable definition. | |
238 | If TYPE is `face', search for a face definition. | |
239 | If TYPE is the value returned by `symbol-function' for a function symbol, | |
240 | search for a function definition. | |
241 | ||
242 | The return value is the absolute name of a readable file where OBJECT is | |
243 | defined. If several such files exist, preference is given to a file | |
244 | found via `load-path'. The return value can also be `C-source', which | |
245 | means that OBJECT is a function or variable defined in C. If no | |
246 | suitable file is found, return nil." | |
247 | (let* ((autoloaded (eq (car-safe type) 'autoload)) | |
248 | (file-name (or (and autoloaded (nth 1 type)) | |
249 | (symbol-file | |
250 | object (if (memq type (list 'defvar 'defface)) | |
251 | type | |
252 | 'defun))))) | |
253 | (cond | |
254 | (autoloaded | |
255 | ;; An autoloaded function: Locate the file since `symbol-function' | |
256 | ;; has only returned a bare string here. | |
257 | (setq file-name | |
258 | (locate-file file-name load-path '(".el" ".elc") 'readable))) | |
259 | ((and (stringp file-name) | |
260 | (string-match "[.]*loaddefs.el\\'" file-name)) | |
261 | ;; An autoloaded variable or face. Visit loaddefs.el in a buffer | |
262 | ;; and try to extract the defining file. The following form is | |
263 | ;; from `describe-function-1' and `describe-variable'. | |
264 | (let ((location | |
265 | (condition-case nil | |
266 | (find-function-search-for-symbol object nil file-name) | |
267 | (error nil)))) | |
6565b5ab | 268 | (when (cdr location) |
1113ff44 MR |
269 | (with-current-buffer (car location) |
270 | (goto-char (cdr location)) | |
271 | (when (re-search-backward | |
272 | "^;;; Generated autoloads from \\(.*\\)" nil t) | |
273 | (setq file-name | |
274 | (locate-file | |
273cefaa GM |
275 | (file-name-sans-extension |
276 | (match-string-no-properties 1)) | |
277 | load-path '(".el" ".elc") 'readable)))))))) | |
1113ff44 MR |
278 | |
279 | (cond | |
280 | ((and (not file-name) (subrp type)) | |
281 | ;; A built-in function. The form is from `describe-function-1'. | |
282 | (if (get-buffer " *DOC*") | |
283 | (help-C-file-name type 'subr) | |
284 | 'C-source)) | |
285 | ((and (not file-name) (symbolp object) | |
286 | (integerp (get object 'variable-documentation))) | |
287 | ;; A variable defined in C. The form is from `describe-variable'. | |
288 | (if (get-buffer " *DOC*") | |
289 | (help-C-file-name object 'var) | |
290 | 'C-source)) | |
291 | ((not (stringp file-name)) | |
292 | ;; If we don't have a file-name string by now, we lost. | |
293 | nil) | |
294 | ((let ((lib-name | |
295 | (if (string-match "[.]elc\\'" file-name) | |
296 | (substring-no-properties file-name 0 -1) | |
297 | file-name))) | |
298 | ;; When the Elisp source file can be found in the install | |
299 | ;; directory return the name of that file - `file-name' should | |
300 | ;; have become an absolute file name ny now. | |
301 | (or (and (file-readable-p lib-name) lib-name) | |
302 | ;; The library might be compressed. | |
303 | (and (file-readable-p (concat lib-name ".gz")) lib-name)))) | |
304 | ((let* ((lib-name (file-name-nondirectory file-name)) | |
305 | ;; The next form is from `describe-simplify-lib-file-name'. | |
306 | (file-name | |
307 | ;; Try converting the absolute file name to a library | |
308 | ;; name, convert that back to a file name and see if we | |
309 | ;; get the original one. If so, they are equivalent. | |
310 | (if (equal file-name (locate-file lib-name load-path '(""))) | |
311 | (if (string-match "[.]elc\\'" lib-name) | |
312 | (substring-no-properties lib-name 0 -1) | |
313 | lib-name) | |
314 | file-name)) | |
315 | ;; The next three forms are from `find-source-lisp-file'. | |
316 | (elc-file (locate-file | |
317 | (concat file-name | |
318 | (if (string-match "\\.el\\'" file-name) | |
319 | "c" | |
320 | ".elc")) | |
321 | load-path nil 'readable)) | |
322 | (str (when elc-file | |
323 | (with-temp-buffer | |
324 | (insert-file-contents-literally elc-file nil 0 256) | |
325 | (buffer-string)))) | |
326 | (src-file (and str | |
327 | (string-match ";;; from file \\(.*\\.el\\)" str) | |
328 | (match-string 1 str)))) | |
329 | (and src-file (file-readable-p src-file) src-file)))))) | |
330 | ||
331 | (declare-function ad-get-advice-info "advice" (function)) | |
332 | ||
333 | ;;;###autoload | |
334 | (defun describe-function-1 (function) | |
335 | (let* ((advised (and (symbolp function) (featurep 'advice) | |
336 | (ad-get-advice-info function))) | |
337 | ;; If the function is advised, use the symbol that has the | |
338 | ;; real definition, if that symbol is already set up. | |
339 | (real-function | |
340 | (or (and advised | |
341 | (let ((origname (cdr (assq 'origname advised)))) | |
342 | (and (fboundp origname) origname))) | |
343 | function)) | |
344 | ;; Get the real definition. | |
345 | (def (if (symbolp real-function) | |
346 | (symbol-function real-function) | |
347 | function)) | |
348 | file-name string | |
349 | (beg (if (commandp def) "an interactive " "a ")) | |
350 | (pt1 (with-current-buffer (help-buffer) (point))) | |
351 | errtype) | |
352 | (setq string | |
353 | (cond ((or (stringp def) | |
354 | (vectorp def)) | |
355 | "a keyboard macro") | |
356 | ((subrp def) | |
357 | (if (eq 'unevalled (cdr (subr-arity def))) | |
358 | (concat beg "special form") | |
359 | (concat beg "built-in function"))) | |
360 | ((byte-code-function-p def) | |
361 | (concat beg "compiled Lisp function")) | |
362 | ((symbolp def) | |
363 | (while (and (fboundp def) | |
364 | (symbolp (symbol-function def))) | |
365 | (setq def (symbol-function def))) | |
366 | ;; Handle (defalias 'foo 'bar), where bar is undefined. | |
367 | (or (fboundp def) (setq errtype 'alias)) | |
368 | (format "an alias for `%s'" def)) | |
369 | ((eq (car-safe def) 'lambda) | |
370 | (concat beg "Lisp function")) | |
371 | ((eq (car-safe def) 'macro) | |
372 | "a Lisp macro") | |
373 | ((eq (car-safe def) 'autoload) | |
374 | (format "%s autoloaded %s" | |
375 | (if (commandp def) "an interactive" "an") | |
376 | (if (eq (nth 4 def) 'keymap) "keymap" | |
377 | (if (nth 4 def) "Lisp macro" "Lisp function")))) | |
378 | ((keymapp def) | |
379 | (let ((is-full nil) | |
380 | (elts (cdr-safe def))) | |
381 | (while elts | |
382 | (if (char-table-p (car-safe elts)) | |
383 | (setq is-full t | |
384 | elts nil)) | |
385 | (setq elts (cdr-safe elts))) | |
386 | (if is-full | |
387 | "a full keymap" | |
388 | "a sparse keymap"))) | |
389 | (t ""))) | |
390 | (princ string) | |
391 | (if (eq errtype 'alias) | |
392 | (princ ",\nwhich is not defined. Please make a bug report.") | |
393 | (with-current-buffer standard-output | |
394 | (save-excursion | |
395 | (save-match-data | |
396 | (when (re-search-backward "alias for `\\([^`']+\\)'" nil t) | |
397 | (help-xref-button 1 'help-function def))))) | |
398 | ||
399 | (setq file-name (find-lisp-object-file-name function def)) | |
400 | (when file-name | |
401 | (princ " in `") | |
402 | ;; We used to add .el to the file name, | |
403 | ;; but that's completely wrong when the user used load-file. | |
e8e8dbf9 MR |
404 | (princ (if (eq file-name 'C-source) |
405 | "C source code" | |
406 | (file-name-nondirectory file-name))) | |
1113ff44 MR |
407 | (princ "'") |
408 | ;; Make a hyperlink to the library. | |
409 | (with-current-buffer standard-output | |
410 | (save-excursion | |
411 | (re-search-backward "`\\([^`']+\\)'" nil t) | |
cebabb67 | 412 | (help-xref-button 1 'help-function-def function file-name)))) |
1113ff44 MR |
413 | (princ ".") |
414 | (with-current-buffer (help-buffer) | |
415 | (fill-region-as-paragraph (save-excursion (goto-char pt1) (forward-line 0) (point)) | |
416 | (point))) | |
417 | (terpri)(terpri) | |
418 | (when (commandp function) | |
63326785 CY |
419 | (let ((pt2 (with-current-buffer (help-buffer) (point))) |
420 | (remapped (command-remapping function))) | |
421 | (unless (memq remapped '(ignore undefined)) | |
422 | (let ((keys (where-is-internal | |
423 | (or remapped function) overriding-local-map nil nil)) | |
424 | non-modified-keys) | |
425 | (if (and (eq function 'self-insert-command) | |
426 | (vectorp (car-safe keys)) | |
427 | (consp (aref (car keys) 0))) | |
428 | (princ "It is bound to many ordinary text characters.\n") | |
429 | ;; Which non-control non-meta keys run this command? | |
430 | (dolist (key keys) | |
431 | (if (member (event-modifiers (aref key 0)) '(nil (shift))) | |
432 | (push key non-modified-keys))) | |
433 | (when remapped | |
434 | (princ "It is remapped to `") | |
435 | (princ (symbol-name remapped)) | |
436 | (princ "'")) | |
437 | ||
438 | (when keys | |
439 | (princ (if remapped ", which is bound to " "It is bound to ")) | |
440 | ;; If lots of ordinary text characters run this command, | |
441 | ;; don't mention them one by one. | |
442 | (if (< (length non-modified-keys) 10) | |
443 | (princ (mapconcat 'key-description keys ", ")) | |
444 | (dolist (key non-modified-keys) | |
445 | (setq keys (delq key keys))) | |
446 | (if keys | |
447 | (progn | |
448 | (princ (mapconcat 'key-description keys ", ")) | |
449 | (princ ", and many ordinary text characters")) | |
450 | (princ "many ordinary text characters")))) | |
451 | (when (or remapped keys non-modified-keys) | |
452 | (princ ".") | |
453 | (terpri))))) | |
1113ff44 | 454 | |
1113ff44 MR |
455 | (with-current-buffer (help-buffer) |
456 | (fill-region-as-paragraph pt2 (point)) | |
457 | (unless (looking-back "\n\n") | |
458 | (terpri))))) | |
a87b98ce GM |
459 | ;; Note that list* etc do not get this property until |
460 | ;; cl-hack-byte-compiler runs, after bytecomp is loaded. | |
461 | (when (eq (get function 'byte-compile) 'cl-byte-compile-compiler-macro) | |
462 | (princ "This function has a compiler macro") | |
463 | (let ((lib (get function 'compiler-macro-file))) | |
464 | (when (stringp lib) | |
465 | (princ (format " in `%s'" lib)) | |
466 | (with-current-buffer standard-output | |
467 | (save-excursion | |
468 | (re-search-backward "`\\([^`']+\\)'" nil t) | |
469 | (help-xref-button 1 'help-function-cmacro function lib))))) | |
470 | (princ ".\n\n")) | |
1113ff44 MR |
471 | (let* ((arglist (help-function-arglist def)) |
472 | (doc (documentation function)) | |
473 | (usage (help-split-fundoc doc function))) | |
474 | (with-current-buffer standard-output | |
475 | ;; If definition is a keymap, skip arglist note. | |
476 | (unless (keymapp function) | |
477 | (let* ((use (cond | |
478 | (usage (setq doc (cdr usage)) (car usage)) | |
479 | ((listp arglist) | |
480 | (format "%S" (help-make-usage function arglist))) | |
481 | ((stringp arglist) arglist) | |
482 | ;; Maybe the arglist is in the docstring of a symbol | |
483 | ;; this one is aliased to. | |
484 | ((let ((fun real-function)) | |
485 | (while (and (symbolp fun) | |
486 | (setq fun (symbol-function fun)) | |
487 | (not (setq usage (help-split-fundoc | |
488 | (documentation fun) | |
489 | function))))) | |
490 | usage) | |
491 | (car usage)) | |
492 | ((or (stringp def) | |
493 | (vectorp def)) | |
494 | (format "\nMacro: %s" (format-kbd-macro def))) | |
495 | (t "[Missing arglist. Please make a bug report.]"))) | |
496 | (high (help-highlight-arguments use doc))) | |
497 | (let ((fill-begin (point))) | |
498 | (insert (car high) "\n") | |
499 | (fill-region fill-begin (point))) | |
500 | (setq doc (cdr high)))) | |
501 | (let* ((obsolete (and | |
502 | ;; function might be a lambda construct. | |
503 | (symbolp function) | |
504 | (get function 'byte-obsolete-info))) | |
505 | (use (car obsolete))) | |
506 | (when obsolete | |
507 | (princ "\nThis function is obsolete") | |
508 | (when (nth 2 obsolete) | |
509 | (insert (format " since %s" (nth 2 obsolete)))) | |
510 | (insert (cond ((stringp use) (concat ";\n" use)) | |
511 | (use (format ";\nuse `%s' instead." use)) | |
512 | (t ".")) | |
513 | "\n")) | |
514 | (insert "\n" | |
515 | (or doc "Not documented.")))))))) | |
516 | ||
517 | \f | |
518 | ;; Variables | |
519 | ||
520 | ;;;###autoload | |
521 | (defun variable-at-point (&optional any-symbol) | |
522 | "Return the bound variable symbol found at or before point. | |
523 | Return 0 if there is no such symbol. | |
524 | If ANY-SYMBOL is non-nil, don't insist the symbol be bound." | |
525 | (with-syntax-table emacs-lisp-mode-syntax-table | |
526 | (or (condition-case () | |
527 | (save-excursion | |
528 | (or (not (zerop (skip-syntax-backward "_w"))) | |
529 | (eq (char-syntax (following-char)) ?w) | |
530 | (eq (char-syntax (following-char)) ?_) | |
531 | (forward-sexp -1)) | |
532 | (skip-chars-forward "'") | |
533 | (let ((obj (read (current-buffer)))) | |
534 | (and (symbolp obj) (boundp obj) obj))) | |
535 | (error nil)) | |
536 | (let* ((str (find-tag-default)) | |
537 | (sym (if str (intern-soft str)))) | |
538 | (if (and sym (or any-symbol (boundp sym))) | |
539 | sym | |
540 | (save-match-data | |
541 | (when (and str (string-match "\\`\\W*\\(.*?\\)\\W*\\'" str)) | |
542 | (setq sym (intern-soft (match-string 1 str))) | |
543 | (and (or any-symbol (boundp sym)) sym))))) | |
544 | 0))) | |
545 | ||
546 | (defun describe-variable-custom-version-info (variable) | |
547 | (let ((custom-version (get variable 'custom-version)) | |
548 | (cpv (get variable 'custom-package-version)) | |
549 | (output nil)) | |
550 | (if custom-version | |
551 | (setq output | |
552 | (format "This variable was introduced, or its default value was changed, in\nversion %s of Emacs.\n" | |
553 | custom-version)) | |
554 | (when cpv | |
555 | (let* ((package (car-safe cpv)) | |
556 | (version (if (listp (cdr-safe cpv)) | |
557 | (car (cdr-safe cpv)) | |
558 | (cdr-safe cpv))) | |
559 | (pkg-versions (assq package customize-package-emacs-version-alist)) | |
560 | (emacsv (cdr (assoc version pkg-versions)))) | |
561 | (if (and package version) | |
562 | (setq output | |
563 | (format (concat "This variable was introduced, or its default value was changed, in\nversion %s of the %s package" | |
564 | (if emacsv | |
565 | (format " that is part of Emacs %s" emacsv)) | |
566 | ".\n") | |
567 | version package)))))) | |
568 | output)) | |
569 | ||
570 | ;;;###autoload | |
571 | (defun describe-variable (variable &optional buffer frame) | |
572 | "Display the full documentation of VARIABLE (a symbol). | |
573 | Returns the documentation as a string, also. | |
574 | If VARIABLE has a buffer-local value in BUFFER or FRAME | |
575 | \(default to the current buffer and current frame), | |
576 | it is displayed along with the global value." | |
577 | (interactive | |
578 | (let ((v (variable-at-point)) | |
579 | (enable-recursive-minibuffers t) | |
580 | val) | |
581 | (setq val (completing-read (if (symbolp v) | |
582 | (format | |
583 | "Describe variable (default %s): " v) | |
584 | "Describe variable: ") | |
585 | obarray | |
586 | '(lambda (vv) | |
587 | (or (boundp vv) | |
588 | (get vv 'variable-documentation))) | |
589 | t nil nil | |
590 | (if (symbolp v) (symbol-name v)))) | |
591 | (list (if (equal val "") | |
592 | v (intern val))))) | |
593 | (let (file-name) | |
594 | (unless (buffer-live-p buffer) (setq buffer (current-buffer))) | |
595 | (unless (frame-live-p frame) (setq frame (selected-frame))) | |
596 | (if (not (symbolp variable)) | |
597 | (message "You did not specify a variable") | |
598 | (save-excursion | |
599 | (let ((valvoid (not (with-current-buffer buffer (boundp variable)))) | |
600 | val val-start-pos locus) | |
601 | ;; Extract the value before setting up the output buffer, | |
602 | ;; in case `buffer' *is* the output buffer. | |
603 | (unless valvoid | |
604 | (with-selected-frame frame | |
605 | (with-current-buffer buffer | |
606 | (setq val (symbol-value variable) | |
607 | locus (variable-binding-locus variable))))) | |
608 | (help-setup-xref (list #'describe-variable variable buffer) | |
609 | (interactive-p)) | |
610 | (with-help-window (help-buffer) | |
611 | (with-current-buffer buffer | |
612 | (prin1 variable) | |
613 | (setq file-name (find-lisp-object-file-name variable 'defvar)) | |
614 | ||
615 | (if file-name | |
616 | (progn | |
617 | (princ " is a variable defined in `") | |
e8e8dbf9 MR |
618 | (princ (if (eq file-name 'C-source) |
619 | "C source code" | |
620 | (file-name-nondirectory file-name))) | |
1113ff44 MR |
621 | (princ "'.\n") |
622 | (with-current-buffer standard-output | |
623 | (save-excursion | |
624 | (re-search-backward "`\\([^`']+\\)'" nil t) | |
625 | (help-xref-button 1 'help-variable-def | |
626 | variable file-name))) | |
627 | (if valvoid | |
628 | (princ "It is void as a variable.") | |
629 | (princ "Its "))) | |
630 | (if valvoid | |
631 | (princ " is void as a variable.") | |
632 | (princ "'s ")))) | |
633 | (if valvoid | |
634 | nil | |
635 | (with-current-buffer standard-output | |
636 | (setq val-start-pos (point)) | |
637 | (princ "value is ") | |
638 | (terpri) | |
639 | (let ((from (point))) | |
640 | (pp val) | |
641 | ;; Hyperlinks in variable's value are quite frequently | |
642 | ;; inappropriate e.g C-h v <RET> features <RET> | |
643 | ;; (help-xref-on-pp from (point)) | |
644 | (if (< (point) (+ from 20)) | |
645 | (delete-region (1- from) from))))) | |
646 | (terpri) | |
647 | ||
648 | (when locus | |
649 | (if (bufferp locus) | |
650 | (princ (format "%socal in buffer %s; " | |
651 | (if (get variable 'permanent-local) | |
652 | "Permanently l" "L") | |
653 | (buffer-name))) | |
654 | (princ (format "It is a frame-local variable; "))) | |
655 | (if (not (default-boundp variable)) | |
656 | (princ "globally void") | |
657 | (let ((val (default-value variable))) | |
658 | (with-current-buffer standard-output | |
659 | (princ "global value is ") | |
660 | (terpri) | |
661 | ;; Fixme: pp can take an age if you happen to | |
662 | ;; ask for a very large expression. We should | |
663 | ;; probably print it raw once and check it's a | |
664 | ;; sensible size before prettyprinting. -- fx | |
665 | (let ((from (point))) | |
666 | (pp val) | |
667 | ;; See previous comment for this function. | |
668 | ;; (help-xref-on-pp from (point)) | |
669 | (if (< (point) (+ from 20)) | |
670 | (delete-region (1- from) from)))))) | |
671 | (terpri)) | |
672 | ||
673 | ;; If the value is large, move it to the end. | |
674 | (with-current-buffer standard-output | |
675 | (when (> (count-lines (point-min) (point-max)) 10) | |
676 | ;; Note that setting the syntax table like below | |
677 | ;; makes forward-sexp move over a `'s' at the end | |
678 | ;; of a symbol. | |
679 | (set-syntax-table emacs-lisp-mode-syntax-table) | |
680 | (goto-char val-start-pos) | |
681 | ;; The line below previously read as | |
682 | ;; (delete-region (point) (progn (end-of-line) (point))) | |
683 | ;; which suppressed display of the buffer local value for | |
684 | ;; large values. | |
685 | (when (looking-at "value is") (replace-match "")) | |
686 | (save-excursion | |
687 | (insert "\n\nValue:") | |
688 | (set (make-local-variable 'help-button-cache) | |
689 | (point-marker))) | |
690 | (insert "value is shown ") | |
691 | (insert-button "below" | |
692 | 'action help-button-cache | |
693 | 'follow-link t | |
694 | 'help-echo "mouse-2, RET: show value") | |
695 | (insert ".\n"))) | |
696 | (terpri) | |
697 | ||
698 | (let* ((alias (condition-case nil | |
699 | (indirect-variable variable) | |
700 | (error variable))) | |
701 | (obsolete (get variable 'byte-obsolete-variable)) | |
702 | (use (car obsolete)) | |
703 | (safe-var (get variable 'safe-local-variable)) | |
704 | (doc (or (documentation-property variable 'variable-documentation) | |
705 | (documentation-property alias 'variable-documentation))) | |
706 | (extra-line nil)) | |
707 | ;; Add a note for variables that have been make-var-buffer-local. | |
708 | (when (and (local-variable-if-set-p variable) | |
709 | (or (not (local-variable-p variable)) | |
710 | (with-temp-buffer | |
711 | (local-variable-if-set-p variable)))) | |
712 | (setq extra-line t) | |
713 | (princ " Automatically becomes buffer-local when set in any fashion.\n")) | |
714 | ||
715 | ;; Mention if it's an alias | |
716 | (unless (eq alias variable) | |
717 | (setq extra-line t) | |
718 | (princ (format " This variable is an alias for `%s'.\n" alias))) | |
719 | ||
720 | (when obsolete | |
721 | (setq extra-line t) | |
722 | (princ " This variable is obsolete") | |
723 | (if (cdr obsolete) (princ (format " since %s" (cdr obsolete)))) | |
724 | (princ (cond ((stringp use) (concat ";\n " use)) | |
725 | (use (format ";\n use `%s' instead." (car obsolete))) | |
726 | (t "."))) | |
727 | (terpri)) | |
2ee20f24 JL |
728 | |
729 | (when (member (cons variable val) file-local-variables-alist) | |
730 | (setq extra-line t) | |
731 | (if (member (cons variable val) dir-local-variables-alist) | |
732 | (let ((file (and (buffer-file-name) | |
733 | (not (file-remote-p (buffer-file-name))) | |
734 | (dir-locals-find-file (buffer-file-name))))) | |
735 | (princ " This variable is a directory local variable") | |
b6ce92f1 CY |
736 | (when file |
737 | (princ (concat "\n from the file \"" | |
738 | (if (consp file) | |
739 | (car file) | |
740 | file) | |
741 | "\""))) | |
2ee20f24 JL |
742 | (princ ".\n")) |
743 | (princ " This variable is a file local variable.\n"))) | |
744 | ||
589a99f2 GM |
745 | (when (memq variable ignored-local-variables) |
746 | (setq extra-line t) | |
747 | (princ " This variable is ignored when used as a file local \ | |
748 | variable.\n")) | |
749 | ||
750 | ;; Can be both risky and safe, eg auto-fill-function. | |
751 | (when (risky-local-variable-p variable) | |
752 | (setq extra-line t) | |
753 | (princ " This variable is potentially risky when used as a \ | |
754 | file local variable.\n") | |
755 | (when (assq variable safe-local-variable-values) | |
756 | (princ " However, you have added it to \ | |
757 | `safe-local-variable-values'.\n"))) | |
758 | ||
1113ff44 MR |
759 | (when safe-var |
760 | (setq extra-line t) | |
761 | (princ " This variable is safe as a file local variable ") | |
762 | (princ "if its value\n satisfies the predicate ") | |
763 | (princ (if (byte-code-function-p safe-var) | |
764 | "which is byte-compiled expression.\n" | |
765 | (format "`%s'.\n" safe-var)))) | |
766 | ||
767 | (if extra-line (terpri)) | |
768 | (princ "Documentation:\n") | |
769 | (with-current-buffer standard-output | |
770 | (insert (or doc "Not documented as a variable.")))) | |
771 | ||
772 | ;; Make a link to customize if this variable can be customized. | |
773 | (when (custom-variable-p variable) | |
774 | (let ((customize-label "customize")) | |
775 | (terpri) | |
776 | (terpri) | |
777 | (princ (concat "You can " customize-label " this variable.")) | |
778 | (with-current-buffer standard-output | |
779 | (save-excursion | |
780 | (re-search-backward | |
781 | (concat "\\(" customize-label "\\)") nil t) | |
782 | (help-xref-button 1 'help-customize-variable variable)))) | |
783 | ;; Note variable's version or package version | |
784 | (let ((output (describe-variable-custom-version-info variable))) | |
785 | (when output | |
786 | (terpri) | |
787 | (terpri) | |
788 | (princ output)))) | |
789 | ||
790 | (save-excursion | |
791 | (set-buffer standard-output) | |
792 | ;; Return the text we displayed. | |
793 | (buffer-string)))))))) | |
794 | ||
795 | ||
796 | ;;;###autoload | |
797 | (defun describe-syntax (&optional buffer) | |
798 | "Describe the syntax specifications in the syntax table of BUFFER. | |
799 | The descriptions are inserted in a help buffer, which is then displayed. | |
800 | BUFFER defaults to the current buffer." | |
801 | (interactive) | |
802 | (setq buffer (or buffer (current-buffer))) | |
803 | (help-setup-xref (list #'describe-syntax buffer) (interactive-p)) | |
804 | (with-help-window (help-buffer) | |
805 | (let ((table (with-current-buffer buffer (syntax-table)))) | |
806 | (with-current-buffer standard-output | |
807 | (describe-vector table 'internal-describe-syntax-value) | |
808 | (while (setq table (char-table-parent table)) | |
809 | (insert "\nThe parent syntax table is:") | |
810 | (describe-vector table 'internal-describe-syntax-value)))))) | |
811 | ||
812 | (defun help-describe-category-set (value) | |
813 | (insert (cond | |
814 | ((null value) "default") | |
815 | ((char-table-p value) "deeper char-table ...") | |
816 | (t (condition-case err | |
817 | (category-set-mnemonics value) | |
818 | (error "invalid")))))) | |
819 | ||
820 | ;;;###autoload | |
821 | (defun describe-categories (&optional buffer) | |
822 | "Describe the category specifications in the current category table. | |
823 | The descriptions are inserted in a buffer, which is then displayed. | |
824 | If BUFFER is non-nil, then describe BUFFER's category table instead. | |
825 | BUFFER should be a buffer or a buffer name." | |
826 | (interactive) | |
827 | (setq buffer (or buffer (current-buffer))) | |
828 | (help-setup-xref (list #'describe-categories buffer) (interactive-p)) | |
829 | (with-help-window (help-buffer) | |
c6ec96f8 KH |
830 | (let* ((table (with-current-buffer buffer (category-table))) |
831 | (docs (char-table-extra-slot table 0))) | |
832 | (if (or (not (vectorp docs)) (/= (length docs) 95)) | |
833 | (error "Invalid first extra slot in this category table\n")) | |
1113ff44 | 834 | (with-current-buffer standard-output |
c6ec96f8 KH |
835 | (insert "Legend of category mnemonics (see the tail for the longer description)\n") |
836 | (let ((pos (point)) (items 0) lines n) | |
837 | (dotimes (i 95) | |
838 | (if (aref docs i) (setq items (1+ items)))) | |
839 | (setq lines (1+ (/ (1- items) 4))) | |
840 | (setq n 0) | |
841 | (dotimes (i 95) | |
842 | (let ((elt (aref docs i))) | |
843 | (when elt | |
844 | (string-match ".*" elt) | |
845 | (setq elt (match-string 0 elt)) | |
846 | (if (>= (length elt) 17) | |
847 | (setq elt (concat (substring elt 0 14) "..."))) | |
848 | (if (< (point) (point-max)) | |
849 | (move-to-column (* 20 (/ n lines)) t)) | |
850 | (insert (+ i ?\s) ?: elt) | |
851 | (if (< (point) (point-max)) | |
852 | (forward-line 1) | |
853 | (insert "\n")) | |
854 | (setq n (1+ n)) | |
855 | (if (= (% n lines) 0) | |
856 | (goto-char pos)))))) | |
857 | (goto-char (point-max)) | |
858 | (insert "\n" | |
859 | "character(s)\tcategory mnemonics\n" | |
860 | "------------\t------------------") | |
1113ff44 | 861 | (describe-vector table 'help-describe-category-set) |
c6ec96f8 KH |
862 | (insert "Legend of category mnemonics:\n") |
863 | (dotimes (i 95) | |
864 | (let ((elt (aref docs i))) | |
865 | (when elt | |
866 | (if (string-match "\n" elt) | |
867 | (setq elt (substring elt (match-end 0)))) | |
868 | (insert (+ i ?\s) ": " elt "\n")))) | |
869 | (while (setq table (char-table-parent table)) | |
870 | (insert "\nThe parent category table is:") | |
871 | (describe-vector table 'help-describe-category-set)))))) | |
1113ff44 MR |
872 | |
873 | (provide 'help-fns) | |
874 | ||
875 | ;; arch-tag: 9e10331c-ae81-4d13-965d-c4819aaab0b3 | |
876 | ;;; help-fns.el ends here |